Service providers have historically managed their networks by placing network management devices at key points in the network. These network management devices monitor network performance and communicate information to backend network operations centers for troubleshooting and corrective action. In the past, Frame Relay and Asynchronous Transfer Mode (ATM) networks provided a capability to provision a management overlay network especially well suited for communication with network management devices. By configuring permanent virtual circuits (PVCs), communication routes could be deployed for reliable communication independent of customer network traffic.
Several factors have eroded the value of the aforementioned approach, including the growth of Internet protocol (IP) and multi protocol label switching (MPLS) networks with mixes of underlying Frame Relay or ATM networks, and the growth of heterogeneous environments where an enterprise is served by multiple service providers. The nature of modem IP and MPLS networks makes configuring “circuit” based point-to-point connectivity extremely difficult if not impossible. These are “mesh” networks by their nature. Even where possible, the heterogeneous environments make configuring and maintaining PVCs prohibitively expensive.
From a network management standpoint, in an MPLS network, ideally one service provider would provide the access for an entire enterprise. This approach would allow the service provider to use an overlay management network to communicate with all of the network management devices on the enterprise's network. However, this scenario is generally the exception rather than the rule. One usually finds that an enterprise network is served by multiple service providers and local exchange carriers (LECs), with one main provider or LEC providing the network management and service level agreement (SLA) guarantees. Additionally, while from the customer's viewpoint, MPLS is being used, the underlying access could be Frame Relay, ATM, point-to-point protocol (PPP), etc.
In such scenarios, setting up the management connections to network management devices can make a rollout of a network management system cost prohibitive. For network management devices connected to a service provider's or LEC's Frame Relay or ATM networks, PVCs must be provisioned, configured, and paid for (as this would be two separate groups in any service provider or LEC) in order to access the network management device. Network management devices that are connected to a competing service provider's or LEC's network are even more difficult to manage. In this case, the main service provider or LEC would have to provision, configure, and pay for access to the competing network (from a second group within its own organization), then buy PVCs to each network management device connected to the competing network from the competing service provider or LEC.
Often, service provider and LEC customers are not willing to endure the cost and time associated with setting up management access to management devices in these types of scenarios. Therefore, a solution is needed that will make such deployments much less costly and much easier to access and manage.